1. Field of the Invention
The present invention relates to a near-field light generator plate, a thermally assisted magnetic head for writing of signals by thermally assisted magnetic recording, a head gimbal assembly (HGA) with this thermally assisted magnetic head, and a hard disk drive with this HGA.
2. Related Background Art
As the recording density of the hard disk drive increases, further improvement is demanded in the performance of the thin film magnetic head. In order to increase the recording density, a recording medium is made of a magnetic material with large KU and the so-called thermally assisted magnetic recording is proposed as a method of applying heat to the recording medium right before application of a writing magnetic field to lower the coercivity of the magnetic material, and then performing writing.
As examples of such thermally-assisted magnetic head recording apparatus, Japanese Patent Application Laid-Open No. 2001-255254 and Japanese Patent Application Laid-Open No. 2003-114184 and T. Matsumoto et al., Near-Field Optical Probe with A Beaked Metallic Plate for Thermally Assisted Magnetic Recording, pp. 6-7, MORIS2006 WORKSHOP Technical Digest, Jun. 6-8, 2003 disclose the thermally-assisted magnetic heads in which an electroconductive near-field light generator plate of a plate shape is disposed on a medium-facing surface and in which light is guided onto the near-field light generator plate from the back side to generate near-field light. Particularly, Japanese Patent Application Laid-Open No. 2003-114184 and T. Matsumoto et al., Near-Field Optical Probe with A Beaked Metallic Plate for Thermally Assisted Magnetic Recording, pp. 6-7, MORIS2006 WORKSHOP Technical Digest, Jun. 6-8, 2003 disclose the structure in which a part of the near-field light generator plate is projected toward the medium, and it is considered that in this structure the near-field light is selectively radiated at high intensity from the projected part toward the medium.